Area of a circle

What does the red line represent?

• The circumference of the circle

• The diameter of the circle

• The radius of the circle

The diameter of a circle is 10 in.

What is its radius?

• 20 in.

• 5 in.

Which ratio is used to calculate Pi?

• C/r

• C/d

• r/C

• d/C

• 98.91 ft.

• 63 ft.

• 197.82 ft.

Does this circle show the radius or diameter?

• radius

• diameter

• radius

• diameter

What is the radius of this circle?

• 40 cm

• 20 cm

• 10 cm

Find the area of a circle with a diameter of 6 inches.

When finding area of a circle, if diameter is given, we need to find radius. We can find radius by ___________ diameter by 2.

• Adding

• Subtracting

• Multiplying

• Dividing